1. Field of the Invention
This invention relates generally to filter apparatus, and particularly to a filter attachment for use with welding and similar face masks.
2. Description of the Prior Art
A serious problem associated with welding operations is the protection of the welder from noxious fumes generated during the welding process. While masks are available on the market to protect the welder from such noxious fumes, these masks generally are quite heavy and very expensive, and accordingly there has been great resistance to their widespread use.
U.S. Pat. No. 3,535,703, issued Oct. 27, 1970, to H. R. Greenlee, discloses a welding helmet in which a fan assembly is disposed adjacent the mouth of a wearer of the helmet for drawing fresh air into the mask from a point generally behind the wear's head, and expelling the air through a forwardly directed opening adjacent the fan assembly.
U.S. Pat. Nos. 3,238,535, issued Mar. 8, 1966, 3,467,965, issued Sept. 23, 1969, 3,584,314, issued June 15, 1971, 3,649,964, issued Mar. 21, 1972, and 3,657,740, issued Apr. 25, 1972, disclose additional examples of face masks and helmets provided with air filtering devices.